Frequencies for first 10,000 rows of tobacco variable in nhamcsopd2003 dataset : tobacco | use/exposur | e | Freq. Percent Cum. ------------+----------------------------------- no | 9,744 97.44 97.44 yes | 256 2.56 100.00 ------------+----------------------------------- Total | 10,000 100.00 by Jean Roth , jroth@nber.org , 28 Mar 2016